The prostate is a gland of the male reproductive system that is located in front of the rectum and just below the bladder. The prostate, comprised largely of muscular and glandular tissue, is wrapped around the urethra, which carries urine from the bladder out through the tip of the penis. Disorders of the prostate are fairly common during the aging process and include prostatitis, benign prostatic hyperplasia (BPH), and adenoma of the prostate, or prostate cancer. Prostatitis, which may or may not be the result of an infection, is generally defined as an inflammation of the prostate. Symptoms associated with prostatitis are pain, voiding symptoms such as nocturia, frequency and urgency of urination, incomplete voiding, and decreased force and/or intermittency of the urinary stream, impotence, and infertility.
Benign prostatic hyperplasia (BPH) is a noncancerous enlargement of the prostate and is common in men over age 40. Symptoms associated with BPH are similar to those observed with prostatitis. Prostate cancer, i.e., adenocarcinoma of the prostate, is the most common malignancy in men greater than 50 years in the US. The incidence increases with each decade of life. Prostate cancer is generally slowly progressive and may cause no symptoms. In late disease, symptoms of bladder outlet obstruction, urethral obstruction, and hematuria may appear and metastasis to the bone may occur.
Diagnosis of urological disorders is often facilitated by a patient's urine flow rate data. Urological disorders such as an obstruction in the lower urological tract or neurotic bladder can be detected by studying the patient's urine flow rate as it varies from the beginning of voiding to the end and the total volume of urine voided. This data can be compared to the mean data for an individual of the same sex and age to help determine the degree of urethral stricture.
Urine flow data is also useful in diagnosing prostrate enlargement. Prostrate enlargement usually occurs gradually with no noticeable impairment to the patient. Merely observing the patient void will usually not enable the urologist or physician to accurately assess the degree of prostate enlargement. However, by observing histograms of the urine flow, the urologist or physician can usually detect the degree of prostrate enlargement and the necessary procedures to be undertaken to correct the disorder. In addition, post-operative urine flow data provides an excellent way of assessing the benefit achieved by surgery.
A variety of urine flow meters for providing urine flow data is presently commercially available. For example, mechanical urine flow meter devices usually comprise a container having a graduated scale for indicating the volume of urine within the container. Urine flow is detected by observing the change in volume as the patient voids into the container. Electrical urine flow meters for providing urine flow data have been developed. These devices may have a urine velocity-measuring apparatus in the form of a urine flow receptacle with a paddle wheel journaled therein. The paddle wheel is mechanically linked to a generator which produces an output voltage which is displayed on a volt meter. The velocity of the urine stream impinging on the paddle wheel determines the paddle wheel velocity and therefore the output voltage of the generator. Other urine flow devices include a urine-receiving receptacle that has a pair of parallel spaced-apart rods or strips disposed therein. The rods or strips are electrically connected to a capacitance sensing circuit. As the volume of urine within the receptacle increases, the capacitance between the rods also increases so that by measuring the rate of change of the capacitance, an indication of the urine flow may be obtained.
As is apparent, current urine flow meters are complex and often require the assistance of a clinician for proper use; moreover, the devices require a high degree of maintenance. Furthermore, since urine contacts components in each of the meters, those components must be cleaned following each use. Therefore, a need exists for a reliable, low maintenance urine flow meter.